diff options
Diffstat (limited to 'arch/ia64/sn/kernel/sn2/timer.c')
| -rw-r--r-- | arch/ia64/sn/kernel/sn2/timer.c | 42 |
1 files changed, 33 insertions, 9 deletions
diff --git a/arch/ia64/sn/kernel/sn2/timer.c b/arch/ia64/sn/kernel/sn2/timer.c index deb9baf4d47..abab8f99e91 100644 --- a/arch/ia64/sn/kernel/sn2/timer.c +++ b/arch/ia64/sn/kernel/sn2/timer.c @@ -11,9 +11,10 @@ #include <linux/sched.h> #include <linux/time.h> #include <linux/interrupt.h> +#include <linux/clocksource.h> #include <asm/hw_irq.h> -#include <asm/system.h> +#include <asm/timex.h> #include <asm/sn/leds.h> #include <asm/sn/shub_mmr.h> @@ -21,16 +22,39 @@ extern unsigned long sn_rtc_cycles_per_second; -static struct time_interpolator sn2_interpolator = { - .drift = -1, - .shift = 10, - .mask = (1LL << 55) - 1, - .source = TIME_SOURCE_MMIO64 +static cycle_t read_sn2(struct clocksource *cs) +{ + return (cycle_t)readq(RTC_COUNTER_ADDR); +} + +static struct clocksource clocksource_sn2 = { + .name = "sn2_rtc", + .rating = 450, + .read = read_sn2, + .mask = (1LL << 55) - 1, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; +/* + * sn udelay uses the RTC instead of the ITC because the ITC is not + * synchronized across all CPUs, and the thread may migrate to another CPU + * if preemption is enabled. + */ +static void +ia64_sn_udelay (unsigned long usecs) +{ + unsigned long start = rtc_time(); + unsigned long end = start + + usecs * sn_rtc_cycles_per_second / 1000000; + + while (time_before((unsigned long)rtc_time(), end)) + cpu_relax(); +} + void __init sn_timer_init(void) { - sn2_interpolator.frequency = sn_rtc_cycles_per_second; - sn2_interpolator.addr = RTC_COUNTER_ADDR; - register_time_interpolator(&sn2_interpolator); + clocksource_sn2.archdata.fsys_mmio = RTC_COUNTER_ADDR; + clocksource_register_hz(&clocksource_sn2, sn_rtc_cycles_per_second); + + ia64_udelay = &ia64_sn_udelay; } |